toyota 4age engine knock

[spudgun GB]

Right then Gents, I might know what this is but could do with a second opinion.

The 4age in my car has a slight knock when cold under throttle. It sounds a bit like valve clearences (which I have since adjusted, and made no notable difference) but a bit louder. Off throtle nothing but if you throttle it a bit, its there. However it is gone within the time it takes me to get out of the village, no more than a two miles and not to be heard again until the morning.
My feelings are that it could be piston slap but any thoughts would welcome.

TIA

[magpie215]

leaking exhaust gasket/cracked exhaust manifold??

when hot expands and seals itself hence no noise after 2 miles??

[spudgun GB]

Cheers for the thought, but its more a whirring knock much more like valve gear than a blowing exhaust. Saying that, its worth a look so I will be out on my back at the weekend.
Thanks for your input.